Priority is claimed to German Patent Application No. 102 10 968.0-24, filed Mar. 13, 2002.
The invention relates to a bent extruded profile, in particular a running rail for movable tops of motor vehicles, comprising a first profile bar and at least one second profile bar which is secured in a form-fitting manner on the longitudinal side of the first profile bar, the securing being brought about by means of formations which substantially correspond to each other and extend on longitudinal sides of the profile bars.
Metal profiles, in particular made of light metal, such as aluminum, can be produced in virtually any desired cross-sectional shape by means of extrusion or related shaping processes. In the motor vehicle sector, in particular, extruded profiles of this type have diverse uses, particularly within the context of xe2x80x9cspace-frame technologyxe2x80x9d which has recently appeared. An area of use for extruded profiles of this type that has likewise appeared recently is the region of movable tops of motor vehicles, in which extruded profiles of this type are used, in particular, as running rails for folding or sliding roofs which can be moved over large regions of the vehicle interior.
Profiles are frequently required which, firstly, have a complex cross section with functionally important structures, some of which are filigree, and, secondly, have to be bent in the longitudinal direction. However, particularly in the case of profiles having a complex cross section and small bending radii in relation to the profile diameter problems occur, in particular when using aluminum as the profile material.
German Patent Document No. DE 196 22 759 A1 describes metal profiles, which can be assembled essentially in accordance with the tongue-and-groove principle in order thus to be able to produce complex profile shapes, in particular when using steel as the profile material. In this case, the proposed tongue-and-groove connections effect a frictional connection between the sub-profiles in all spatial directions from the outset. In a subsequent bending of the profiles, this does not give rise to any differences from a single profile manufactured from a solid material.
German Patent Document No. DE 100 15 986 A1 describes a composite profile in which a first profile consisting of metal has lateral grooved sockets, and a second profile consisting of plastic uses corresponding formations to engage in the grooved sockets. The grooved sockets of the first profile are dimensioned in such a manner that a gap generally remains even after engagement of the second profile, the dimensioning serving to compensate for dimensional tolerances of the profiles in the region of their mutual engagement. The profiles can be secured to one another in a form-fitting manner in all of the directions perpendicular with respect to the longitudinal direction by webs of the grooved sockets of the first profile being plastically molded after engagement of the profiles, with, preferably, resilient longitudinal means also being placed between the profiles in the region of the grooved socket. The direction of deformation here is exclusively perpendicular with respect to the longitudinal extent, so that the profiles which are as a result connected to one another are secured on one another in a form-fitting manner in transverse directions, but merely non-positively or frictionally in the longitudinal direction. Bending of the profiles about an axis perpendicular with respect to the longitudinal extent is not envisaged, with the result that compressions and distortions of the material in the longitudinal direction of the profile do not occur.
It is an object of the invention to specify a bent extruded profile and a method for producing a bent extruded profile, in which particularly small bending radii can be produced with respect to bending the profile using bending techniques known per se.
The present invention provides a bent extruded profile, in particular a running rail for movable tops of motor vehicles, that includes a first profile bar, at least one second profile bar which is secured in a form-fitting manner on the longitudinal side of the first profile bar, the securing being brought about by means of formations which substantially correspond to each other and extend on longitudinal sides of the profile bars, and at least one passing gap being provided in the region of the corresponding formations, wherein, prior to being bent, it is possible for the profile bars, which are secured to each other, to be moved relative to each other in the longitudinal direction, and wherein a completely form-fitting connection of the profile bars to each other is achieved after bending of the profile bars.
According to the invention, the two profile bars here are secured on each other in a form-fitting manner in their longitudinal direction such that they can be moved relative to each other prior to being bent in the longitudinal direction, the provision of the passing gap in the region of the corresponding formations enabling the material which is compressed during bending to be deflected, the passing of the compressed material into the passing gap preventing, in particular in the region of small bending radii, the profile material from tearing or preventing the profile material from being deformed perpendicular with respect to its longitudinal direction. A bent extruded profile according to the invention also comprises designs in which more than two profile bars are secured on each other.
In a preferred embodiment of a bent extruded profile according to the invention, the corresponding formations have an essentially dovetailed or swallowtailed cross section, with a first and a second passing gap being provided in each case in the region of corners of the dovetailed or swallowtailed cross section and a further passing gap being provided in the region of a projection of the dovetailed or swallowtailed cross section. This provision of a plurality of passing gaps and the dovetailed shaping permit the extruded profile to be bent in different directions, with different passing gaps in each case receiving the material bulges when bending it in different directions.
A bent extruded profile according to the invention preferably has a cross-sectional shape essentially in the form of a U, as a result of which the bent extruded profile is especially suitable for use as a running rail for movable tops of motor vehicles.
The bent extruded profile particularly preferably consists of aluminum, since this material, in particular, is generally increasingly being used in the construction of motor vehicles, although limits are imposed with regard to its bending capability. As an alternative to this, a bent extruded profile according to the invention may, however, also consist of magnesium or steel or of another metal, since the improvement, which is associated with the present invention, in bending radii which can be achieved applies, in principle, for all of the materials from which bent extruded profiles can be produced. In particular, the second profile bar may also consist of a different material than the first profile bar.
The extruded profile according to the invention particularly preferably has, at least in some regions, a bending radius, which is less than four times the profile diameter present in the bending direction. By achieving ratios of this type between the profile height or diameter and the bending radius, particularly great flexibility in the shaping of structural parts produced firstly via an extrusion process can be achieved.
A method for producing a bent extruded profile according to the invention comprises the following steps:
1. Production of a first profile bar and at least one second profile bar according to an extrusion process known per se, the first profile bar having a lateral formation and the second profile bar having a formation which corresponds in a form-fitting manner to the lateral formation of the first profile bar;
2. Connecting the at least two profile bars in a form-fitting manner by inserting the lateral formation of the first profile bar into the lateral formation of the second profile bar, as a result of which a form-fitting connection is achieved in all directions except for the longitudinal direction of the profile bars;
3. Bending of the connected profile bars by means of a bending process known per se, wherein, after bending, a completely form-fitting connection of the profile bars to each other is achieved.
By this means, a bent extruded profile is produced in a simple manner without additional tools or machines in comparison with conventional processes having to be used.
In a preferred method according to the invention, the lateral formations of the profile bars produced by method step 1 are preferably designed in such a manner that after the form-fitting connection according to method step 2, a passing gap remains between the two lateral formations. This permits a further improvement in the bending radii which can be achieved during bending in accordance with method step 3, since the material being compressed during the bending process can pass into the passing gap before excessive distortion of the material and tears or cracks can occur. Further features and advantages of the invention emerge from the exemplary embodiment described below and from the claims.